Sound reproducer



. March 20, 1928.

G. C. LlNDSEY SOUND REPRODUCER Filed Sept. 18. 1,925 2 Sheets-Sheet 1 March 20, 1928.

G. C. LINDSEY SOUND REPRODUCER Filed Sept. 18. 1925 2 Sheets- Sheet 2 uns-712% L1 il (Se l.

v Gig-0 6a ,Br a d Pas e M... 20, 1928.

UNITED STATES PATENT OFFICE.

0mm; LINDSEY, or LOS antennas, camronma, ASSIGNOB or SEVEN 'rnm'rir- SECONDS '10- MICHAEL .GOZZO, ONE-EIGHTH TO DON EMINGEB, SIX THIRTY-SECONDS .IO VICTOR P. .HENDRICK, AND FOUR THIRTY-SECONDS TO ROBERT TURNER.

SOUN D BEPRODUCER.

Application filed September 18, 1925. Seriallo. 57,153.

\ oar In the improved construction there is a supportin board and two sounding boards mounted t ereon. "An electro-magnetic unit of somewhat conventional construction is' mounted upon the supporting board and has its vibrator or clapper engageable, upon or connected to the sounding board so that the the sounding board.

With the foregoing and other objects in view which will-be made manifest in the following detailed description and s ecifically polnted out in the appended c aims, reference ishad to the accompanying drawings for an illustrative embodiment of the invention, wherein; I I

Figure 1 is a perspective view of the improved sound reproducing device.

Fig. 2- is a vertical section taken substantially upon the line 22 of Fig. 1.

Fig. 3 is a partial side elevation of the device, parts being broken away, illustratin the unit.

' ig. 4 is a horizontal section taken upon the line -44 of Fig. 3.

Fig'.- 5 is a perspective view of a sound reproducing device of slightly modified form of construction. a v

Fig. 6 is a vertical section taken upon the line 6-6 of'Fig. 5. e I I Fig. 7 is a partial view illustrating the electro-magnetic unit employed on the construction shown-in Figs. 5 and 6.

Fi 8 'is a horizontal section taken upon the line 8 8 of Fig. 7.

wherein similar reference characters designate slmllar parts throughout, the 1mproved sound reproduclng device consists of a base 10, on which. isvertically mount-' ed a supportin board 11. Preferably two sounding boar s 12'and13 are mounted upvibrations may be transmitted directly to onthe supporting board 11, althoughone sounding board may prove sufficiently satisfactory. These sounding boards are curved,

having their top vand bottom edges secured I to the supporting board and have their central portions in spaced relation thereto, dividing air pockets 14: and 15 upon both sides of the supporting board.- A bracket 16 is fastened tothe supporting board 11 above the aperture 17 therein.- and'a-unitsupport:

ing member 18 is hingedly connected thereto as indicated at 19. A suitable adjusting screw 20 is mounted upon the supporting board-and engages tlmlower endof the unit supporting member18.for adjusting it relatively to'the sounding board 13.

On the unit su porting member there is mounted a suitab e support 21' which su ports a permanent'horseshoe magnet 22, t e

support 21 is mounted upon the unit supoi't'in-g member 18 by means of rubber cushlOIlS 23.v The legsof the horseshoe magnet 22- are connected by means of a plate 24 and suitable struts 25, having knife ed es projecting from the plate. Coils-26 w ich are adapted to be connected to the radio receiv ing set are arranged between the legs of the magnet 22 upon the supporting member 21. On the unit supporting member 18 there is threaded an adjusting screw 27'which carries a clapper or vibrator 28 having a needle "29 which is not fixed to but presses against the sounding board 13 with a varying ressure. A screw 30 extends throu h the vlbrator 28 and isfastened to the unit, and a coil spring 31 is compressed between the headof t e screw 30 and the vibrator, owe the end of the vibrator to engage the ed es of the strut. 25.

a he 0 eration of the device is believed to r be readi y apparent. The coils together with the permanent magnet 22 produce the vibrations ofthe vibrator or, clapper 28 and as the needle 29 presses against theisounding board .13, the sounding board will be v1- brated by the variations in pressure of the needle, thus producing the sound. The vol- Referring to the accompanying drawings,

ume of the sound may be varied by varying the pressure under which the needle 29 presses against the sounding board adjusting the screws 27 and 20.

A peculiar feature of the im roved construction is that the sound pro ucedcan be heard from-all sides of the device, but there is a slightly greater volume directly opposite the sides of the sounding boards.

The improved construction eliminates the use of a diaphragm which in reproducingsounds of large volume is apt to be overcrowded or overvibrated so as to become noisy. I In the modified form of construction shown in Figs. 5 to 8 inclusive, there is a base 35, a supporting board 36, sounding boards 37 and 38 which are similar in construction to the'base supporting .board and sounding boards of the construction shown inFigs. 1 to 4 inclusive. In this modification however, a bracket 39 is fastened to the 'is indicated at and is rigidly fastened to the sounding board 38. By adjusting the adjusting screw -42 the magnitude of the vi-v brations imparted to the sounding board 38 by the vibrator or clapper 45 can be varied and thus the volume of sound produced can be varied. From the above described construction it will be readily appreciated that an improved form of sound reproducing device has been provided which is simple and efficient in operation and eliminates disagreeable noises. It will also be appreciated that the'complete device may be supported on any suitable supporting. structure and is neat'and attractive in appearance.

Various changes may be made in the details of construction without departing from 'the spirit or scope of-the invention as defined by the appended claims.

What I claim is: p

1'. A sound reproducer comprising a support, a sounding board carried by the sup port, an electro-magnetic operating unit pivotally mounted on the support to permit,

swinging movement of the unit relative to the sounding board, means carried by the support engaging the swinging unit for adjusting the unit relative to the sounding board, a. spring-tensioned vibrator having at one end a pivotal mounting on the unit and being non-connected to but pressing against the. sounding board at its opposite swinging end for vibrating the sounding board, the medial portion of the vibrator overlying the actuatingmechanism of the unit for vibration thereby, and means carried by the operating unit engaging the swinging end of the vibrator for adjusting the vibrator relative to the operating unit and the sounding board.

2. A sound repro'duce'r comprising a sound responsive medium, an operating unit adapted to swing relative to the sound responsive medium, a vibrator carried by and adapted to swing-relative to the operating unit, said vibrator being actuated by the operating unit and adapted to vibrate the sound responsive medium, adjusting means for swinging theoperating unit relative to the sound responsive medium, and adjusting means for swinging the vibrator relative to the operating unit and the sound responsive medium. 3 .j

3. A sound reproducer comprising a sound responsive medium, an operating unit, a vibrator having at one end a spring tensioned pivotal mounting on the operating unit, the medial portion of the vibrator overlyingthe actuating mechanism of the operating unit for vibration thereby, the

opposite swingingend of the vibrator being non-connected to but pressing .against' the sound responsive medium for vibrating the latter, and means for adjusting the swinging end of the vibrator relative to the operating unit and the sound responsive medium. 7

In testimony whereof Ihave signed my name to this specification.

GEO. C. LINDSEY. 

